But I will point out that you should not use E.C. as a target in preparing nutrient.

Yeah I'm aware that EC is just a heuristic for the nutrient levels and actually measures the amount of ionic salts. That's why I wanted to use ROed water; to minimize that amount of unusable salts in the water making nutrients more effective and water uptake easier on the plants.

What fertilizer are you using?

It's in the OP, but I see the formatting got messed up a little bit. It's Envy A+B, so yeah it's a 2 part mixture. That's what I looked at the back of to notice that no copper was present. Funny, I ordered GH's set today and have TPS's full set coming as well.